PHARYNGEAL/ BRACHIAL ARCH DERIVATIVES
| A | 1st pharyngeal arch | |
| B |
2nd pharyngeal arch |
|
| C |
4th pharyngeal arch |
|
| D |
3rd pharyngeal arch |
Which of the following pharyngeal arches develops into epiglottis?
| A |
1st pharyngeal arch |
|
| B |
2nd pharyngeal arch |
|
| C |
4th pharyngeal arch |
|
| D |
3rd pharyngeal arch |
| Pharyngeal arch | Muscular contributions | Skeletal contributions | Nerve | Artery |
| 1st (also called “mandibular arch”) | Muscles of mastication, anterior belly of the digastric, mylohyoid, tensor tympani, tensor veli palatini | Maxilla, mandible (only as a model for mandible not actual formation of mandible), the incus and malleus of the middle ear, also Meckel’s cartilage | Trigeminal nerve(V2 and V3) | Maxillary artery, external carotid artery |
| 2nd (also called the “hyoid arch”) | Muscles of facial expression, buccinator, platysma, stapedius, stylohyoid, posterior belly of the digastric | Stapes, styloid process, hyoid (lesser horn and upper part of body), Reichert’s cartilage | Facial nerve (VII) | Stapedial artery, hyoid artery |
| 3rd | Stylopharyngeus | Hyoid (greater horn and lower part of body), thymus, inferior parathyroids | Glossopharyngeal nerve (IX) | Common carotid, internal carotid |
| 4th | Cricothyroid muscle, all intrinsic muscles of soft palate including levator veli palatini | Thyroid cartilage, superior parathyroids, epiglottic cartilage | Vagus nerve (X), superior laryngeal nerve |
Right 4th aortic arch: subclavian artery
Left 4th aortic arch: aortic arch
|
| 6th | All intrinsic muscles of larynx except the cricothyroid muscle | Cricoid cartilage, arytenoid cartilages, corniculate cartilage | Vagus nerve (X), recurrent laryngeal nerve |
Right 6th aortic arch: pulmonary artery
Left 6th aortic arch: pulmonary artery and ductus arteriosus
|
Ref: Langman Embryology, 11 Edition, pg. 277
The stapes is embryologically derived from the following pharyngeal arch ?
| A |
1st arch |
|
| B |
2nd arch |
|
| C |
3rd arch |
|
| D |
4th arch |
The second pharyngeal arch gives rise to Reichert cartilage, which eventually forms:
- Manubrium of the malleus
- Long process of the incus
- Stapes suprastructure
- Tympanic portion of the stapes footplate
- Facial nerve
- Muscles of facial expression
- Stapedius muscle
- The upper portion of the hyoid bone
- Stylohyoid ligament
| A |
First arch |
|
| B |
Second arch |
|
| C |
Third arch |
|
| D |
None of the above |
The cartilage of the second or hyoid arch (Reichert’s cartilage) gives rise to the stapes, styloid process of the temporal bone, stylohyoid ligament, and ventrally, the lesser horn and upper part of the body of the hyoid bone.
Ref: Langman’s embryology 11th edition Chapter 16.
Musculature of first pharyngeal arch is supplied by which cranial nerve?
| A |
V |
|
| B |
VII |
|
| C |
IX |
|
| D |
X |
Musculature of the first pharyngeal arch includes the muscles of mastication (temporalis, masseter, and pterygoids), anterior belly of the digastric, mylohyoid, tensor tympani, and tensor palatini. The nerve supply to the muscles of the first arch is provided by the mandibular branch of the trigeminal nerve
Ref: Langman’s embryology 11th edition Chapter 16.
The stapes is a derivative of which of the following pharyngeal arch?
| A |
1st arch |
|
| B |
2nd arch |
|
| C |
3rd arch |
|
| D |
4th arch |
Structures derived from second pharyngeal arch are stapes, styloid process of temporal bone, lesser cornu of hyoid bone and upper part of hyoid bone.
|
First arch |
Malleus and incus
Portions of the mandible
Meckels cartilage
Sphenomandibular ligament
Anterior ligament of malleus
|
|
Second arch |
stapes
Styloid process of temporal bone
Lesser cornu of hyoid bone
Upper part of hyoid bone
|
|
Third arch |
Greater cornu of hyoid bone
Lower part of hyoid bone
|
|
Fourth arch |
Thyroid cartilage
Cricoid cartilage
Arytenoid cartilage
Corniculate and Cuneiform cartilage
|
Following statements are true regarding first pharyngeal arch :
| A | Maxillary & mandibular prominences are formed | |
| B | Maxilla & Zygomatic bone are formed by intermembranous ossification | |
| C |
Tensor palati formed by first arch |
|
| D |
All |
A i.e. Maxillary & mandibular prominences are formed; B i.e. Maxilla & Zygomatic bone are formed by intermembranous ossification; C i.e. Tensor palati formed by first arch
All of the following muscles are derived from Pharyngeal Arches, Except:
| A |
Tensor Tympani |
|
| B |
Levator Palpebrae superioris |
|
| C |
Palatine Tensor |
|
| D |
Orbicularis oculi |
B i.e. Lavator palpebral superioris
All of the following are derrived from pharyngeal arches except:
| A |
Tensor Tympani |
|
| B |
Palatine Tonsils |
|
| C |
Mylohyoid |
|
| D |
Tensor veli Palatini |
Ans. B i.e. Palatine Tonsils
- Tensor tympani, tensor veli palatine (i.e. palatine tensor) & mylohyoidQ develop from 1st (mandibular pharyngeal arch; orbicularis oculi & orbicularis oris develop from 2nd (hyoid)) pharyngeal or branchial arch. Whereas, levator palpebrae superioris is a somatic muscle that develops from prochordal mesenchyme
- Palatine tonsils and tonsillar fossa are derived from (2nd) pharyngeal pouch and not from pharyngeal arches
| A |
Posterior belly of digastric |
|
| B |
Anterior belly of digastric |
|
| C |
Buccinator |
|
| D |
Platysma |
Anterior belly of digastric is derived from first pharyngeal arch
Derivatives of 2nd pharyngeal arch
- Stapes,
- Styloid process,
- Stylohyoid ligament, and
- Lesser cornu of the hyoid bone.
- Muscles of face
- Occipitofrontalis muscle
- Platysma
- Stylohyoid muscle
- Posterior belly of Digastric
- Stapedius muscle
- Auricular muscles
| A | 1st | |
| B |
2nd |
|
| C |
3rd |
|
| D |
4th |
4th
1st pharyngeal arches – Mm. masseter, temporalis, pterygoids
2nd pharyngeal arches – Mimic musculature:
Mm. Stylohyoideus, digastricus (venter posterior) and stapedius
3rd pharyngeal arches – M. stylopharyngeus
4th pharyngeal arches- Almost the entire pharynx and larynx musculature
5th pharyngeal arches and cervical somites- M. sternocleidomastoideus and trapezius
Skeletal derivative of 2°’ pharyngeal arch –
| A |
Malleus |
|
| B |
Incus |
|
| C |
Stapes |
|
| D |
Maxilla |
Ans. is `c’ i.e., Stapes
